Transforms a string of a custom field

Any idea? any recommendations?

<?php
$fileuri = ‘https://domain.com/wp-content/uploads/2008/09/image.jpg&#8217;;

$extention = ‘.’ . end(explode(‘.’, $filename));
$finalfileuri = substr($fileuri, strripos($fileuri, ‘.’)) . ‘-225×150’ . $extention;

if it does’nt work, try this:

$finalfileuri = substr($fileuri, strripos($fileuri, ‘.’)-1) . ‘-225×150’ . $extention;

strripos= tr2.php.net/manual/en/function.strripos.php
substr= tr2.php.net/manual/en/function.substr.php
end= tr2.php.net/manual/en/function.end.php

Thank you very much, was very useful! ??